Fire bricks for heat storage

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dannimac

New Member
Oct 4, 2021
12
Glasgow, Scotland
U.K. based first time poster. Have searched and can’t see that this has been asked before.

I have a Morso Squirrel with an ecofan in the living room of a 2 up 2 down terraced house, insulated and with new double glazing.

I want to make the most of the heat I’m generating from the stove. There’s no way of having a back boiler or venting.

I’ve read about putting fire bricks beside the stove to store and radiate heat after the fire has died down. I’ve also read that moving the bricks to some of the colder rooms would help radiate some heat in them.

I bought some Vitcas bricks to try this out but I now realise I bought the wrong kind for this purpose (insulating rather than accumulating).

I’m not sure what type to actually buy now!

Does anyone have any recommendations? I know this won’t necessarily heat the room up but any kind of marginal gain of heat would be worth it.

Thanks in advance for any help given.
 

begreen

Mooderator
Staff member
Nov 18, 2005
89,794
South Puget Sound, WA
Soapstone bricks or slabs? Otherwise red clay brick maybe.
 

stoveliker

Minister of Fire
Nov 17, 2019
1,615
Long Island NY
The heat "content" of bricks is rather low. If you want to heat up some material for spreading the heat output (in time or to other spaces by moving it), I'd figure out a way to use water. Metal buckets with a lid? Water has a much higher heat capacity, meaning you'll be moving a lot more heat to the other room with the same weight of material.
 

EatenByLimestone

Minister of Fire
Hunks of steel work too. Tubs of water should work better, but you use what you've got!

I collected a bunch of stones I heat up on the stove, and use them to dry the inside of boots out. Just drop hot stones down into the boot!

Probably all these suggestions will be far less beneficial that making sure you are running your stove as well as possible. Dry wood and proper operation will get the most out of your stove. Blowers and fans can help a lot too.
 

begreen

Mooderator
Staff member
Nov 18, 2005
89,794
South Puget Sound, WA
Large flat stones used to be warmed up on the hearth, then put in the bed under the covers to warm it.
 

EbS-P

Minister of Fire
Jan 19, 2019
1,260
SE North Carolina
I’ve also read that moving the bricks to some of the colder rooms would help radiate some heat in them.
I think a fan on the floor moving cold air to the stove would work better. Im to tired to attempt the math. Remember the stove only put out so much heat per load into the house. We are taking about storing that energy. So for every 100kg of brick we heat up something else in the house is not getting that energy. I hung a blanket across my stairs. floor to ceiling on the first floor so all the heat didn’t just go straight up stairs when I wanted the first floor to be warmer.
 

Poindexter

Minister of Fire
Jun 28, 2014
2,382
Fairbanks, Alaska
Welcome dannimac. I have never met a Glaswegian I didn't like. We remain, USA and UK, two countries separated by a common language.

What is a two up/ two down? How many square feet or meters are you trying to heat?

I found a Morso squirrel here: https://morsoe.com/us/product/indoor/wood-burning-stove/p1410_us#m-technical-data , a fairly small stove by US standards, firebox 3/4 of one cubic foot.

Assuming a two level home, can all of your family sleep on the upper level where the heat is going to be, or do you have teenagers at home?
 

moresnow

Minister of Fire
Jan 13, 2015
1,796
Iowa
Maybe a larger stove with fan/blower?
 

dannimac

New Member
Oct 4, 2021
12
Glasgow, Scotland
The heat "content" of bricks is rather low. If you want to heat up some material for spreading the heat output (in time or to other spaces by moving it), I'd figure out a way to use water. Metal buckets with a lid? Water has a much higher heat capacity, meaning you'll be moving a lot more heat to the other room with the same weight of material.
Thanks for the reply. Not overly keen on the idea of buckets of water. Small house, big dogs, hot water- accident waiting to happen.

Was looking for recommendations for types of fire bricks that would work.
 

dannimac

New Member
Oct 4, 2021
12
Glasgow, Scotland
Hunks of steel work too. Tubs of water should work better, but you use what you've got!

I collected a bunch of stones I heat up on the stove, and use them to dry the inside of boots out. Just drop hot stones down into the boot!

Probably all these suggestions will be far less beneficial that making sure you are running your stove as well as possible. Dry wood and proper operation will get the most out of your stove. Blowers and fans can help a lot too.
Thanks for replying. I have an ecofan on top of my stove and it does make a real difference. Don’t want to increase any electricity consumption. I use ecologs so very dry wood.
 

dannimac

New Member
Oct 4, 2021
12
Glasgow, Scotland
Welcome dannimac. I have never met a Glaswegian I didn't like. We remain, USA and UK, two countries separated by a common language.

What is a two up/ two down? How many square feet or meters are you trying to heat?

I found a Morso squirrel here: https://morsoe.com/us/product/indoor/wood-burning-stove/p1410_us#m-technical-data , a fairly small stove by US standards, firebox 3/4 of one cubic foot.

Assuming a two level home, can all of your family sleep on the upper level where the heat is going to be, or do you have teenagers at home?
Thanks, Poindexter. We Glaswegians are a direct but affable bunch.

2 up 2 down is shorthand for the number of rooms on each floor (excl bathroom). No clue on square footage- small by small!

2 adults and 2 dogs here- all sleep upstairs but it’s the upstairs that’s cooler that I’m trying to get a little more heat in to.

My stove is a variation on the Squirrel but figured that model was better known. Small for US standards but almost too powerful for us! Just need to get some of that heat out of our living room and spread elsewhere.
 

stoveliker

Minister of Fire
Nov 17, 2019
1,615
Long Island NY
ok. If you're trying to get heat up, see if you can make an air loop. So that hot air can go up (stairwell?) and go down through another route. That greatly helps convection.
 

SpaceBus

Minister of Fire
Nov 18, 2018
6,147
Downeast Maine
Put a fan at the top of your stairs blowing down. This should establish an convective loop and move that heat upstairs.
 

begreen

Mooderator
Staff member
Nov 18, 2005
89,794
South Puget Sound, WA
Thanks for reply. Is soapstone quite robust?
Yes, and you may be able to get scraps from a job, like a kitchen counter from a mason. Or chunks cut from an old soapstone sink.
 

Poindexter

Minister of Fire
Jun 28, 2014
2,382
Fairbanks, Alaska
I haven't tried it on a two story layout, but I think a convective loop is worth a try. Can you put a really small fan, like 6" (maybe ~15-20 cm) in diameter at the top of the stairs near floor level to blow cool air on the floor of the upper level out into the stairwell so it can drift gently down the stairs?

Set the fan on low, extra low, really slow, nip around to the pub for 3-4 hours and then decide if it is working or not when you get home. An effective convective loop is very much like a languid placid river and nothing at all like the exhaust of a jet airplane engine.

Like stoveliker and spacebus are talking about, a convective loop, but a good one (in my experience) is a whispering thing, not a loud shouter. You want to just tip the cold air off the edge of the upper floor so it can sort of meander down the treads and risers while leaving plenty of airspace above for the hot air to rise.

It is a fairly uncommon problem, typically here the upper level of a home gets uncomfortably hot when the room with the woodburner in it on the lower level becomes comfortably warm.

No offense if nipping around to the pub isn't a thing that is said in Glasgow, I have a good friend from the midlands of England a few cousins south of E-burg in the borders country. I spent about 20 minutes on the phone this morning with various pharmacies in town (chemists?) that all had voice recognition software on their phone systems. This week, before 0900 on Monday, I internet searched on "Scottish elevator youtube" (again) (there is a version with subtitles) and had to watch it, twice, before I could get back to work.

Best of luck to you. If the small fan doesn't work we will come up with something else, but carrying stone up and down the stairs is a bit of bother.
 
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Poindexter

Minister of Fire
Jun 28, 2014
2,382
Fairbanks, Alaska
I just had to watch the elevator thing again. I spent enough time in North Carolina that voice recognition doesn't work very well for me either.

If the six inch fan doesn't work, the next thing I would try would be a smaller fan, like a 4"/ 10cm unit out of a computer power supply that will probably run on 12 volts DC, like the charger for an electric shaver. Let that run all day while you are at work before you decide if it is working.
 

dannimac

New Member
Oct 4, 2021
12
Glasgow, Scotland
I haven't tried it on a two story layout, but I think a convective loop is worth a try. Can you put a really small fan, like 6" (maybe ~15-20 cm) in diameter at the top of the stairs near floor level to blow cool air on the floor of the upper level out into the stairwell so it can drift gently down the stairs?

Set the fan on low, extra low, really slow, nip around to the pub for 3-4 hours and then decide if it is working or not when you get home. An effective convective loop is very much like a languid placid river and nothing at all like the exhaust of a jet airplane engine.

Like stoveliker and spacebus are talking about, a convective loop, but a good one (in my experience) is a whispering thing, not a loud shouter. You want to just tip the cold air off the edge of the upper floor so it can sort of meander down the treads and risers while leaving plenty of airspace above for the hot air to rise.

It is a fairly uncommon problem, typically here the upper level of a home gets uncomfortably hot when the room with the woodburner in it on the lower level becomes comfortably warm.

No offense if nipping around to the pub isn't a thing that is said in Glasgow, I have a good friend from the midlands of England a few cousins south of E-burg in the borders country. I spent about 20 minutes on the phone this morning with various pharmacies in town (chemists?) that all had voice recognition software on their phone systems. This week, before 0900 on Monday, I internet searched on "Scottish elevator youtube" (again) (there is a version with subtitles) and had to watch it, twice, before I could get back to work.

Best of luck to you. If the small fan doesn't work we will come up with something else, but carrying stone up and down the stairs is a bit of bother.
Eleven!

One of my favourite sketches of all time.

I’m sure your friends and family will have told you of our current energy price crisis so I’m looking for a solution with no increase to electricity consumption. I’m hoping if the bricks/stones work out that I can also help out neighbours with them. Every little counts this winter.

And tbh I could do with the exercise of having to take stones/bricks upstairs!
 

stoveliker

Minister of Fire
Nov 17, 2019
1,615
Long Island NY
I see. The point of spacebus was that it is more efficient to move cold dense air to the stove than warm air from the stove.

Not to belabor my point, but the stone will be hot too (dogs). Moreover, water has a volumetric heat capacity of 4.18 J/cm3 K whereas soap stone has about 3 J/cm3 K. This means that moving the same volume of water )and at the same temp) upstairs gets you about 40% more heat upstairs. AND by only carrying 1/3 of the weight.

So, carrying 1/3 of the mass gives you 40 % more heat. And you'll likely have to pay for soap stone when water is comparably cheap (almost free for the quantity you would be using).

You're free to do as you wish, but I wanted to make clear that at the same temperature (and same danger level), the physics dictates that the most efficient solution is not soap stone. Convenience is of course an aspect that is hard to quantify.
 
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SpaceBus

Minister of Fire
Nov 18, 2018
6,147
Downeast Maine
Something not accounted for in the water is the weight of the vessel, which must be able to stand up to the stove heat as well, so not really 1/3 the equivalent weight of stone when you account for that. Maybe something with a tight fitted, but ventilated, lid might be OK to prevent sloshing. If this is a squirrel stove it's a 2b standard or 1410, both have small tops for limited heating ability. Perhaps leaving a large open vessel of water on the top is a better plan. The winter months are usually dry enough and the hot moist air might be encouraged up the stars with a decent convective loop.

I do understand the need for less electric use, but a small computer fan is not going to be noticeable in your electric bill. Our electricity here in Maine is some of of the most expensive in the colonies, so I really do understand. Like Poindexter said, you don't want a huge fan. One that you can't hear would be ideal for the speed of air movement you want and low electrical draw. If any kind of fan assisted air movement is out of the question you could try and see if there is a place to put a cold air return in the same room as the stove. It would allow the air to "pour" down which *should* force the hot air to rise up the stairwell.

I looked up your rates and a small fan for this purpose would cost 0.02 pence per day or even less. This would raise your bill by less than one quid per month.